SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07ece5acfb748ebd9e462ac435b63b69bf7e62047edeccbda3989e81f745fac2' 
  AND token = 'pxqBIrJGVXNdHKPMF3uj/OTLzK1WfC4iTLTUY+rnH3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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