SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df470da959c69738c72095156bdd2844cf2d6fd45c7934b79b1d6566b06be554' 
  AND token = '7StTLMy5wwdU89gyCWZkICOFOwqDwlXIaYOcKh92oXI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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