SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbcc38b576912f5a6397d306245735e8421a08455c49dff62790f2815085629e' 
  AND token = 'HxNOI9S+8nzDbazinS+Dwq181h0RZl48vsivNEOBERs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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