SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f09ea156324326fdabb85f520bb1f739958f13de869960659125b84d55e84597' 
  AND token = 's8ZBxzuxab0KyUqV1/rCCb0sTNuzI8I/8u3Lyl/cXco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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