SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7cb88425485eed5e764ffb635e68ff9462e7a92af65ae6841f321e4c88a2ebc' 
  AND token = 'hU0LBaOYuXlwlUEk+9u68ZLKa+bc7MYVRuDV+mtrjeo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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