SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '12d333379e563d50209741ac09374a0e1ffd98a86a71dbac2dbf1b619bcf0d9c' 
  AND token = 'yw1txyH6FNuOg3La+IwaxpLN7x99mFvRQ/MN3JzGTAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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