SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5988b85c5153d7a2ed985ed4a9e1f9055ae733aea65e5e6152dfd0b350e4a960' 
  AND token = 'PkIqscoIiA90cn7sp1XwsHYN8GDaFPriuxzuXgUkyP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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