SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '575f48433092ac416017b4d0ab3047f5fbb32b549c5bd20ff7ddce5ec7da3093' 
  AND token = 'tjw5BKsRZzftLGEZGspEfBRrK3JqDRbygnwY7O7Hzs4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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