SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71763f436ec9dd4d4a22f7122ac83d4df7cbf87eee11ed8441a09fa0533e9a30' 
  AND token = '5Y/TVYJsCu7FOKPlmzM68/iG2OfD0LyojJcZVRPHZqY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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