SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d2a668c9ab2c9cccc9d5dff915641c8de253c44459aac9fb11ff6fda9e10a51' 
  AND token = 'yy0e16BOLaMzNqkaQr/FqvULpQIoqBv4e5EqnV8UQ3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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