SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1689e099a64c22bbd8258c154894cb7bb636b104026a1ed2c62d4a10e28ba128' 
  AND token = 'eS67LWXlKo93BcLMrSOCnRjw6i/njlNnWAm8/K4Hl6w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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