SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b03f755fdec4feeecfd052e4fc56829d98cf8e46dff004265bd66a3ae86bb4fe' 
  AND token = '+W9ngjL3zWi9wIJFFXOcelsW3kLXoZFD4tm25IDhAdc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}