SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37de8bc1e967685fad6556da85bd8121d17365bc073be07a8cf7d3604347cbae' 
  AND token = 'N6tLIACNHDpFiVekWisuctzFoy8y692784zT7mR+JZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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