SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3be5a643612459083c389362c4fb79522cfec4ea94379974eb0812fc2be36d53' 
  AND token = 'zTLP6qg52qgdjGJZ6MY23w6WPm+E/lfKCufX8lllHfs=' 
  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"
    }
  }
}