SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0dbbf7086c5cb6bc1c820f5e9f2555c14d6b552dc8ca907937bd136975af0b16' 
  AND token = 'A99DBDihdRELmq/VWkdlfmCdca6Dmj+bBaBBfl+a3rk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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