SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2040d735f558405314ee035e9f260ddbe3ac74ac17cdd3433ba0e365804a096' 
  AND token = 'VLkk/wFk9jJJbhtSv3gjvT9i/w6QP1bCHHX0X+d/ua8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00198

JSON explain

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