SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da4a6dbca1d14538ec03ae57f0516ec0b869ffec7269b8678cc74cb0ad8519f0' 
  AND token = 'HBqQCrY/REzAo3F3cJicJ0jUNgRbBaV9AsRiZ+OAvK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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