SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2159a231429e8a4afd4e00aa5ad099726126f252135d3f8067b7dc376f134e5' 
  AND token = 'hDCn0eoSTFBDi/0DArURVeEc1zDxXP4IQ7zydPIYgrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}