SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc931dc0506bdc50c6697b5bf01a0848f66f30994909e097c1ac7234bfb4c692' 
  AND token = 'xMwCxjgKVB+RaeK5sLOUmTOiZSBE6447orgetxUrvpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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