SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8dfa13ec2dbebd185766d9c1071d918d1e52e7cf79655f068e2597114beadf9d' 
  AND token = 'HbRyk7QaYBQyoTjEQs2576D2azNp+FaYtyiAHK0p7BY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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