SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd3be721762a5043f451c9ea765d71354592aebce49e883b7a7e2d9052fb68cf9' 
  AND token = 'dNwYTxvfK6eSLJOqzAfRi1Sp1+qV9ueuHcpSJ9iZ07w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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