SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c9f829fde3ffe393bc88a58844b2ff6b5dded99adb906db389bd164aef295da' 
  AND token = 'JBYWSvkot1cPbqW288U1rU0nmLAGuMN2w4Prm4VG60M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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