SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '218866c9d978c49f5b41f05465fdf57eee81cecfe944b1abb59c6b27e809652a' 
  AND token = 'y+z3lz+4gDYlnr/mVVXbkAv8GV+5j5vRM9P+Xya5sGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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