SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f2ef673fb7c53c0c528c1fc1cdfc63f9ff1ef37e10189184273f17581e936cf' 
  AND token = '3wXZq32sl44ICvI30JjynOP/HLRcLmgRhGNJ5kPbegk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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