SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '539824473b3ef4976cc4b5e90fbd74c6371cc92ec31c5bcd1b10e853dc0d7bda' 
  AND token = 'g97BEFHs/2bYX6JxPukryoeHgfi+elCK3k5QuMrB6Vs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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