SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '941301c34ef4ca60b78beaf0f5371fa6ab07245deff383e2116c98ebef5c3e8d' 
  AND token = 'xfB1hRMPxh6xy7ZophrMQJwqaeyyBtG2KcHHSMmuXok=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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