SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43a29680a19cfe6353c4b2324f891190a9d7e22716e95a8134e71caeedb43e29' 
  AND token = 'jJnDeza2whfeyxt6CAJabwURk7BTWLag7PBST+esTug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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