SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88fe3f7c664c37568e988bbce9f87d2f77f8b74c79c46d6712352b4e6c8fb1ea' 
  AND token = 'DDTKgainkSRXBRcVQnG0N+LPunC32e4Ewzk0On8feKM=' 
  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"
    }
  }
}