SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b91d9d0af9d77fb1636c4e542b95b1107d2c27aef35dd4ce0a6d879b643cf97' 
  AND token = 'kCDQh84agoWAfGF2jEgP+wgFiftJa3VC5GbKBkNRCzo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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