SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c429a52499175be6a683f9fb80d9d4b69a83dc6880246c13213d0ea327c96533' 
  AND token = 'fP1XvuVr4XwBBhaKSJHWPVOZDdUKZrhJPE8ufcNuFos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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