SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e74cdee76f7f3d18dbb257eb374a5baaef15cfa9b64dc0bc07ff7e236ae33f86' 
  AND token = 'M1hekyJbgE7YXaSoxeUTTdfjdSVypVtPWHDGVoFuINw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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