SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bea19781bc2ec233453f3321997e6a7aac45e7f963ff1f84cc40192d8dd8c73f' 
  AND token = 'cIOEehJg9DPveGMmY0wxBNSXOAqpnICY9qNBT+8GLdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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