SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e37da350819805ae9b731d3abd4386492d077e8d5af471d85a429fabfcea08d1' 
  AND token = '2J3GetPjKLDGMXphWmANQjWjEfbknBnMXYUpg+EfOog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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