SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdbcb61a7a6ede9254b65c509dd682c297d7a70ee6a02db8589245749b25c7cd' 
  AND token = 'eQaCBA2j1Bu8OqgUuijj0b+sS5OZ5aROTzyOWPfvuKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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