SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '08457ac2500b26a0421a7168f8c91032081af3bf4a000e479a09b4daf0062284' 
  AND token = '+7BKorQVaLKwpcxJ51s/sqOzn/mqnEtm5GehYaR1lVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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