SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'adf35e20723accc62d4e86cb1c83bda7592f974b417564e389d61b5b5eed96f1' 
  AND token = 'qV3b8ijpcqmbcSA0tSkR8F/QhX/7iC1ZM2kI0R+iupQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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