SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea8dafa86b50a6843cbd057a016a5353ac22517d3ee086618f1cbb63a9cee364' 
  AND token = 'pJKOztIKpNyVT/NJ1wToLa9crK8teLw3WrzaGNboLn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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