SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1186c543d56c18df407c07b19d3bedb94063987331f70a9788eb17b59938213' 
  AND token = 'DGqQgzqXEOqF1c2hZw/DVxi6TKFF/sRRUfda6n3hwd0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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