SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27095647fef476aac5f1ebb18dab116d286de757460123ebe690dc4b12885b7e' 
  AND token = 'VryMSLS3qPgG3KWifqy19styWifDJ0uouiE+EJLUJ5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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