SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4373032be912b3cb6c00a0652761764e755a0ebef99ff2d2b037c68f05e7a2f3' 
  AND token = 'mURV0EnAc0i+ySOWJZMRnm8Nb1UvrsI0PKtdCf+h4HM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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