SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb774243d404251de65250860ff3d45ee85001eba64fff565799be2ae819d23c' 
  AND token = 'rw3K0mRvxiUqrmWQfJdSlSny9dlm1Lq/NEI24fgZrGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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