SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60e3c6c6771e27ff5f613b918fcb86f2e445b7e181325003b5467c1869bf121c' 
  AND token = '5KzJfBswjZh/hKLtNCRkLHdtJBdfCdVRP/zH+TIclK4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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