SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3c88d72cf6b1932fb0a69e2bc46028d66c7238901b2cad805b2a22f7b548b91' 
  AND token = 'SNQR9LZpDHQVUl+4PivNGxKWA/uu/xEyvKml2G8ewcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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