SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa983905490899b8961eaf41a2a91c01bc548b61925a89f1f7112ca960abf7ff' 
  AND token = 'zNK+equGGNqKnaywXmgdIPlCSFgupFfhB+HcJu4xxjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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