SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cedb5d9b9312cf699658102996dc9d1242cca1d99d825863efd9b3d995da3f64' 
  AND token = 'sVWdexWiQ3tnQVmjqGXkaI4NgOAkTpz60H14O8070n8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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