SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a28f32ebce4d1a4495337fccca9258313f0d59e838b0c0bc4acef90685bf985' 
  AND token = 'LdyGP6NAhXSeQ0gVxrhnB09wOA9cCcHBUtaZGyh4pSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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