SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '636970a5bb522620fe1013010b1cca82de80afaae8ffae467c135090b04010fb' 
  AND token = '9ZaDNQqZgbr4WorUskPYCfvBy/5xD/GUmmag4PHbuzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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