SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd4fc4a8218bfaa5950c82ada17bcfecf7861f98d55909218fdd22bed39bce8e6' 
  AND token = '2y6gnj0UYg5Rlmmnxdx4+LsFqKBR52KEtpXmv4nQQcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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