SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6346746ebc7f8e699e2e01da16cab70f5b18b61181f91bb632d3f023a8221c97' 
  AND token = 'PyeQQRAi01kJePz1daFGR5rjJ97EBAgRLCpGnrlnJ34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00007

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}