SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '782ef89f1b9c3d2c54ea1d5bf9f3373c5ca8260bfb95dafa6acca5895da9f4c7' 
  AND token = 'Fw8HXJK/MFp/sFdy5ThkGJyK1rIcSWNv8bpqK2pkiNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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