SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c507157204903dd01cd0d31aadbbbef1d119556d25b2c8e6416d5bf87e120b80' 
  AND token = 'Dy0ll9ERMxJBtvZhsHCg3zV7mKLWfnMMzc9D0gA1knY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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