SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8913a846d4806e35c9be4872d395354f00d5c616368c22b2583367acf9fa6756' 
  AND token = 'z/x0vlXNeh3aZVdRwRjsscBsHR1ag6+ihxYtx99r2/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00008

JSON explain

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