SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c53aebc11697a8532ed0d31731ee7c5c531cbc28a35fb56997479ba22524ad9b' 
  AND token = 'mU4ZHUXs56EdiINAextIW/hcsgNmSeMJ8tZbWlCJTQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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