SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '00c8f749b53f08e0419d1d9929c36608be14e4335619a09b096892f765ba5da5' 
  AND token = 'nR+scldEvLMajRhBy0pzIJVK4yBXnGWDX809EHm+xME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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