SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9b22fb5f51816c199ae3632ff745b15c04701ef1ea72f3a65fd8654967c511f' 
  AND token = 'MCo3UtMg5cKjD90bQsQICIEK65utAb+dTNRPi9LJEpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}