SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd69a99f4d5f6371d2f10a79a593a04bbdce165d268b94a2521af2235505ae16a' 
  AND token = 'EwlqHqGAMijTbdo092JUvSGuvTgPHAwqxOuT809dw/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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