SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c095b82f78daede376920242b08780d55638ba8876b3de3ef5d07b0c645494a4' 
  AND token = 'hOHINEDmEQYUs/z/jzYFrBx3mZ+eNAUUCrBnL9tapgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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