SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38b280131747bb808c8f369f6a46c2565a59864b4c1f65f2ac960d795373a39d' 
  AND token = 'c5nR1yKuJUoB0VI/pGZO/7BLMQrF8unvagdfHVwF0uo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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