SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6bd64856a8eaedb5e2711388363f0f27bb555a0e3996711d20a88ccda019f278' 
  AND token = 'z7L6AfEVMG3iiNq16CoOZBvTggihvoszOntkPBBdR1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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