SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edc1c760d5915281382991055c79ba328a360cfd1eb9061ea767bde75e78d96c' 
  AND token = 'Jc+J12kXDQREuo3uWIBT6aOQPCWxCmCfhTQZvNs5lso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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