SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc4e96a37d1ab9ad6a32cc6e66228bc4f398c0de1ef9027eff557e45369afe76' 
  AND token = '+bQKXGvqC7XsK3SrNZ+AxIqIJOFh3H1haoJGXKerW3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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