SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89251825b4172295e35c33b922921e788612840c3d4e8fa0c8a2547b668f14b1' 
  AND token = 'm/rOdl2/Nk9gdL1e9AwvDr7Tqgv7IRKj0pSpnxHlJQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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