SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af4819104246425cd447dd66632217ee677e14adb8575e258ef9f966b95b88bb' 
  AND token = '4AUEgcDykGQvJ97XXvsRTLoWJnuS5MIAPoXP35IfSQ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}