SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9571bf8983cf58f0a77f4e21bf032c02787881dadc3d321385bf408570f2568e' 
  AND token = 'ipp7wNF7684kptbfwXU18WkKSxOtdmK/46sbiZjIxxw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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