SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bfa8ddbbe794f064c3cadc9a4ccc1e1ec4c012972ec03074ad58e83a688e872' 
  AND token = 'pxbFJ6zbWNqr5EcG3hoZFOn8s73HZgArI3ud0xjHiAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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