SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '815e09215282cd31fe6568173fdbbecc79957aec4b4b66b8a21c8717dd4d4fc3' 
  AND token = 'NF+Ep/cLU6L1qnB/O0wQImudQFd/J+GjXv79q94db0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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