SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c98e0e564b72e49493991bb9281f1d1177ca1107edb051eca033e9505054cfef' 
  AND token = '7WbslHw9Hi4EOWE7Vcu0nAilOVIFcenc7kO2vRki780=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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