SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0fed9470893c25f0f8264825257328b9bfae6e2a6ec9b4a7d551e7d90d8d708' 
  AND token = 'WqAIpYkJKSNf/m1grLBFsCBgbo6POoxoEbOy8xPFyyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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