SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbb3f2e9600c9964e11915345e74265d24aba486298f956ada60b969bffd9ba5' 
  AND token = '0jxAgzaQo75P8SwVyHqdZRLN/YZ9/o4QDhpVjW3WDaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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