SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd02d1e1648622b55a3cc47d17e457b875952901488581e2b54d3ddbe7b0e9cdf' 
  AND token = 'AP9y3Cm+HW93C9PIXtCi9oeApae2Cy1i67y4NLNQMg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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