SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6efd50890fb430007dc4ee093c0d46ba2d619fdbed646f283136dbb41032bd53' 
  AND token = 'n6RSpESqZtMSt4xm682cTgbSnvN2gRDl4GfWoE0gv7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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