SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ce3a8b0d4f4c3f1db9e8ef5899ccc48312d0630c510a73ad67b02ea46669b5b' 
  AND token = 'MFjSilPkbqVFqBmxjB6RCGRRAf2p9JCRDzCHnSEJDTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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