SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12e1d289fdb91f4598df0aec008c391ed865b07d577a25b33639b055c5edefdd' 
  AND token = 'Lej604Fxv+ykAncpNHgkpmmPksvq2qT5iv1zm4lf69c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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